Cardiocondyla verdensis, Seifert, 2023

Seifert, Bernhard, 2023, A revision of the Palaearctic species of the ant genus Cardiocondyla Emery 1869 (Hymenoptera: Formicidae), Zootaxa 5274 (1), pp. 1-64 : 47

Cardiocondyla verdensis n. sp.

Etymology: name referring to the type locality—an island within the Cape Verde Archipelago.

Type material:

Holotype plus 1 paratype on the same pin labeled “ C. VERDE: 16.588°N, 24.328°W, Sao Nicolao , 385 m, 1 km SW Cabecalinho, trees, CV-192, J.Wetterer 2003.07.21 ”; depository: collection of X. Espadaler.

All material examined. Only the type sample was available. For details see supplementary information SI1, SI2.

Geographic range. Only known from the type locality.

Diagnosis: --Worker ( Tab. 3 , Figs. 82–85 ). Rather small, CS 503 µm. Head longer than in any species of the C. batesii group, CL/CW 1.247. Postocular index rather small, PoOc/CL 0.371. Median third of hind margin of head feebly concave. Scape longer than in any species of the C. batesii group, SL/CS 0.860. Eye large, EYE/CS 0.266. Frons moderately wide (FRS/CS 0.254), frontal carinae very weakly converging immediately caudal of FRS level (FL/FR 1.042). Dorsal profile of promesonotum convex, metanotal depression deep (MGr/CS 4.50 %), dorsal profile of propodeum convex. Propodeal spines short (SP/CS 0.096) but very acute and moderately steep, their angle in lateral view differing by 45° from longitudinal axis of mesosoma; their bases approached (SPBA/CS 0.230). Petiole distinctly higher than wide (PeW/CS 0.271, PeH/CS 0.312); in profile with a short but rather thin peduncle, a straight to weakly convex anterior face and a strongly convex dorsal profile. Postpetiole moderately wide and rather low (PpW/CS 0.519, PpW /PeW 1.92, PpH/CS 0.264), in dorsal view with a slightly concave anterior margin; postpetiolar sternite completely flat. Clypeus on whole surface smooth and shiny but its lateral areas finely longitudinally carinulate. Frontal lobes and area posterior of the frontal lobes smooth but areas adjacent to frontal carinae longitudinally carinulate. Vertex with the smallest foveolae seen in the C. batesii group (dFOV 8.0 µm), the interspaces between the foveolae completely smooth, in places with very delicate stickman-like microstructures ( Fig. 85 ). Dorsal mesosoma smooth and shiny, with very small foveolae and delicate stickman-like microstructures. Meso- and metapleurae shiny but notably microreticulate, surface of the bulla glandulae metapleuralis longitudinally carinulate. Petiole and postpetiole very smooth and shiny but very delicately microreticulate. Pubescence on gaster tergites short and more dilute than in other species of the C. batesii group, PLG/CS 5.24 %, sqPDG 5.90. Head, mesosoma and gaster concolorous dark brown.

Taxonomic comments and clustering results. Despite the isolated position of the Cape Verde Archipelago 600 kilometers off the African continent, these islands are apparently not poor in species. Within only nine samples available from Cape Verde, the author could detect four species: Cardiocondyla emeryi Forel 1881 , C. fajumensis Forel 1913 , C. nigra Forel 1905 and C. verdense n. sp. Most likely all these species (or their ancestors) were introduced from Africa. Passive anthropogenous introduction, beginning with the Portuguese colonization in the 15th century, should have played a major role. Cardiocondyla verdensis n. sp. is interpreted here as an endemic island species having developed extreme shape characters as a consequence of genetic bottle necking after introduction. According to data in Tab. 3 , C. verdense n. sp. is a combination of extreme values of CL/CW, SL/CS, dFOV and of large sqPDG. The type sample is placed widely separate from the C. nigra cluster in a PCA considering the 14 characters CS, CL/CW, SL/CS, PoOc/CS, EYE/CS, dFOV, SP/CS, PeW/CS, PpW/CS, PeH/CS, PpH/CS, sqPDG, PLG/CS and MGr/CS ( Fig. 142 ). Apart from its extreme morphometrics it is in overall impression similar to the dark and shiny morph of C. nigra of which the next place of occurrence is the island Sao Vicente, 50 km overseas from Sao Nicolao.

Biology. The type sample was collected in a garden with trees within a semidesert landscape.

Figures

FIGURE 142. Separation of nest samples of Cardiocondyla nigra (white dots, n=45) and C. verdense (black square, n=1) by a principal component analysis considering the morphometric characters CS, CL/CW, SL/CS, PoOc/CS, EYE/CS, dFOV, FRS/ CS, SPBA/CS, SP/CS, PeW/CS, PpW/CS, PeH/CS, PpH/CS, sqPDG, PLG/CS and MGr/CS. The grey dot represents a C. nigra sample from the Cape Verde island Sao Vicente. The type samples of C. bicoronata, C. nigra and C. torretassoi are marked by the letters B, N and T.

FIGURES 82–85. Cardiocondyla verdensis n. sp., holotype; Fig. 82: head in dorsal view; Fig. 83: lateral view; Fig. 84: dorsal view; Fig. 85: head surface between inner eye margin and paramedian vertex. Cape Verde: Sao Nicolao, 2003.07.21